Vulnerability · Published Oct 4, 2021 · Assigned by GitHub_M
CVE-2021-32675DoS vulnerability in Redis
High 7.5
In plain English
A high-severity resource allocation without limits in redis from redis. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 16.1% (higher than 97% of all known vulnerabilities). Ready-made attack tooling exists: public proof-of-concept code. Fixed versions are available - upgrade the affected package.
Official description
Redis is an open source, in-memory database that persists on disk. When parsing an incoming Redis Standard Protocol (RESP) request, Redis allocates memory according to user-specified values which determine the number of elements (in the multi-bulk header) and size of each element (in the bulk header). An attacker delivering specially crafted requests over multiple connections can cause the server to allocate significant amount of memory. Because the same parsing mechanism is used to handle authentication requests, this vulnerability can also be exploited by unauthenticated users. The problem is fixed in Redis versions 6.2.6, 6.0.16 and 5.0.14. An additional workaround to mitigate this problem without patching the redis-server executable is to block access to prevent unauthenticated users from connecting to Redis. This can be done in different ways: Using network access control tools like firewalls, iptables, security groups, etc. or Enabling TLS and requiring users to authenticate using client side certificates.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux:8 | redis | 5.0.3-5.module_el8.4.0+2583+b9845322 | ALSA-2021:3918 |
| AlmaLinux:8 | redis | 5.0.3-5.module_el8.5.0+66+fc19ec12 | ALSA-2021:3918 |
| AlmaLinux:8 | redis | 6.0.9-5.module_el8.5.0+67+a3c431d9 | ALSA-2021:3945 |
| AlmaLinux:8 | redis | 6.0.9-5.module_el8.4.0+2584+1bb0d2aa | ALSA-2021:3945 |
| AlmaLinux:8 | redis-devel | 6.0.9-5.module_el8.4.0+2584+1bb0d2aa | ALSA-2021:3945 |
| AlmaLinux:8 | redis-devel | 6.0.9-5.module_el8.5.0+67+a3c431d9 | ALSA-2021:3945 |
| AlmaLinux:8 | redis-devel | 5.0.3-5.module_el8.5.0+66+fc19ec12 | ALSA-2021:3918 |
| AlmaLinux:8 | redis-devel | 5.0.3-5.module_el8.4.0+2583+b9845322 | ALSA-2021:3918 |
| AlmaLinux:8 | redis-doc | 5.0.3-5.module_el8.4.0+2583+b9845322 | ALSA-2021:3918 |
| AlmaLinux:8 | redis-doc | 6.0.9-5.module_el8.4.0+2584+1bb0d2aa | ALSA-2021:3945 |
| Alpine:v3.20 | redis | 6.2.6-r0 | ALPINE-CVE-2021-32675 |
| Alpine:v3.21 | redis | 6.2.6-r0 | ALPINE-CVE-2021-32675 |
| Alpine:v3.22 | redis | 6.2.6-r0 | ALPINE-CVE-2021-32675 |
| Alpine:v3.23 | redis | 6.2.6-r0 | ALPINE-CVE-2021-32675 |
| Alpine:v3.24 | redis | 6.2.6-r0 | ALPINE-CVE-2021-32675 |
| Debian:12 | redis | 5:6.0.16-1 | DEBIAN-CVE-2021-32675 |
| Debian:13 | redis | 5:6.0.16-1 | DEBIAN-CVE-2021-32675 |
| Debian:14 | redis | 5:6.0.16-1 | DEBIAN-CVE-2021-32675 |
| Rocky Linux:8 | redis | 0:6.0.9-5.module+el8.4.0+660+a8447b97 | RLSA-2021:3945 |
| Rocky Linux:8 | redis | 0:6.0.9-5.module+el8.5.0+658+72172854 | RLSA-2021:3945 |
| Rocky Linux:8 | redis | 0:5.0.3-5.module+el8.4.0+659+cf535ef1 | RLSA-2021:3918 |
| Rocky Linux:8 | redis | 0:5.0.3-5.module+el8.5.0+657+2674830e | RLSA-2021:3918 |
Affected products (as reported)
Weakness: CWE-770 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
References
- https://github.com/redis/redis/security/advisories/GHSA-f6pw-v9gw-v64p x_refsource_CONFIRM
- https://github.com/redis/redis/commit/5674b0057ff2903d43eaff802017eddf37c360f8 x_refsource_MISC
- FEDORA-2021-8913c7900c vendor-advisory, x_refsource_FEDORA
- FEDORA-2021-61c487f241 vendor-advisory, x_refsource_FEDORA
- [geode-notifications] 20211013 [GitHub] [geode] jdeppe-pivotal opened a new pull request #6994: GEODE-9676: Limit array and string sizes for unauthenticated Radish connections mailing-list, x_refsource_MLIST
- FEDORA-2021-aa94492a09 vendor-advisory, x_refsource_FEDORA
- DSA-5001 vendor-advisory, x_refsource_DEBIAN
- https://www.oracle.com/security-alerts/cpuapr2022.html x_refsource_MISC
- https://security.netapp.com/advisory/ntap-20211104-0003/ x_refsource_CONFIRM
- GLSA-202209-17 vendor-advisory, x_refsource_GENTOO